Current balancing reactors for diodes



July 19, 1960 G. A. HEALl's CURRENT BALNCING REACTORS FOR DIODES 2 Sheets-Sheet 1 Filed may 5, 195e urli. Il

Patented July 19, 1960 United States Patent Otice v 2,945,961 'CURRENT BALANCING REA-CTORS FOR DIODES' George A. Healis, Palmyra, NJ., assignor to I-T-E Circuit Breaker Company, Philadelphia, Pa., a corporation of Pennsylvania Filed May s, A195s,serLNo.732,868

r3 Claims. (cl. 307-58) 324, describes a system for balancing the current be? tween a plurality of parallel connected diodes by coupling each pair of adjacent diodes with -a commonreactor core. Since there may be as `many as twenty or more parallel connected rectiers to be coupled', it was found that the use of individual coupling reactors leads to an extremely complex and expensive system. `y

' I have found that the plurality of individual'coupling reactors can be replaced by a single stack of ilat stamped magnetic laminations having apertures in registry with each of the diode conductors to be coupled where a first portion of the laminations of the stack couple a given diode conductor with a first adjacent diode and a second portion of the laminations couple the same diode with a second adjacent diode. In this manner, each pair of adjacent diodes of a parallel connected group will be coupled by a magnetic path in the same manner as if individual coupling reactors were used. Furthermore, by appropriately designing the laminations, anv open or closed chain of coupling reactors Lcan be formed.

i I have further constructed the system so that the coupling iron is supported from the main current carrying bus work to thereby further -amplify the mechanical structure of a rectifier system using a substantial number of diode elements.

Accordingly, a primary object of my invention is to provide a novel coupling reactor system.

Another object of my invention is to provide a current balancing system for parallel connected diodes which is simple and economical.

`Another object of my invention 4is to form a coupling magnetic circuit `for magnetically coupling a plurality of pairs of adjacent diodes which is vformed lfrom a stack of punched laminations, y `f Y Still another object of my invention is to provide a novel laminated sheet structure for the balancing reactors of a plurality of parallel connected diodes where the i reactors are Vsupported from the ybus bars of thesystem. These and other objects of my invention will become apparent from the following description when taken in conjunction with the drawings, in which vFigure l s hows fa single phase half-wave rectifier having'a plurality Iof parallel connected diode elements.V

' .Fi'gureZ shows the manner in which lthe diodes of Figure l can be coupled by coupling reactors to force an equal current distribution betweenthe diodes lwhere the coupling chain is open.

Figure 3 is similar to Figure 2 where the chain o-f coupling reactors 'is closed.

Figure 4 shows another manner -in which kthe chain of Figure 2 can be closed.

Figure 5 shows a perspective view of the manner in which a stack of stamped laminations may provide the same magnetic circuits asv an open chain of coupling reactors.

Figure 6 shows atop view of one of the laminations of a rst group of laminations where the laminations are to form a closed chain. v l

Figure 7 shows a top view of one of the laminations of a second group of laminations which are to form a closed chain.

Figure 8 shows a top view of the'v lamination of Figure 6 positioned with respect -to the lamination of Figure 7.

Figure 8a shows the manner in which an air gap may be inserted into the laminations of Figure 5.

Figure 9 shows the manner in which the lamination stacks of Figure 8 can be supported from the bus structure in a partially cross-sectional View.

Figure l0 is a View of Figure 9 taken across the linesy 10-10.

Referring now to Figure l, the single phase, half-wave rectiiier is shown therein to merely illustrate how a plurality of diodes are connected in parallel to achieve a particular current rating of a system. Thus, a\A.-C.l source 20 is connected to a D.C. lo'ad 22 through eight parallel connected diodes 24, 26, 28, 30, 32,' 34, 36 and 38.

As is fully described' in above noted copending applicationSerial No. 628,324, the forward currentrconducted by each of the diodes will be different in accordance with the forward conduction characteristic of each diode. Therefore, as seen in Figure 2, the conductors 40, 42, 44, 46, 48, 50,52 and 54 -associatedwith diodes 24, 26, 28, 30, 32, 34, '36 and 38 respectively are interconnected by coupling reactors which force equal current `distribution between the diodes.

Y Hence, eachl adjacent pair of diode conductors are magnetically connected by coupling reactors 56; 58, 60, 62, 64, 66 and 68. More speciically, conductors 40'and 42 are linked by reactor 56, conductors 42 and 44 are linked by reactor 58, conductors 44 and 46 are linked by reactors 60 and so on. It is to be noted that the conductors of each pair are arranged to conduct current in opposite directions through their respective reactor, as indicated by the convention of a dot, indicating current ilowl away from the plane of the drawing and a cross indicating current ilow into the plane of the drawing. Since the operation ofthe coupling reactors of Ithe drawings is the subject matter of above noted application Serial No. 628,324, reference is made thereto fork operational details. Y While Figure k2 shows the so-called "open chain type of coupling for forcing equal current distribution between the diodes 24-38 associated with conductors 40-54respectively, the chain may be closed, as shown in Figure -3` by a further coupling reactor 70 which couples conductors` 54 and 40. l If there are an odd number of parallel connected'diodes rather than the even number of Figures 1, 2 and 3, the chain may be closed as in Figure 4 by providing auxiliary reactors 72 and '74 for conductors 40 and S2 respectively where eachof auxiliary reactors 72 Y and 74 have air gaps 76 and 78 respectively and windings 80 and 82 respecgether. Clearly, many other types of closing a loop of even or odd numbers of diodes are available, the methods shown herein being for purposes of illustration.

Figure 5 shows a rst embodiment of my invention where a stack of stamped laminations form an equivalent of an open chain of couplet reactors. Figure 5 shovvs the diode conductors 4.0 through 54 as being magnetically related through a stack of magnetic laminations having a Iirst portion 9,0 and a second potrion 92. Each lamination of first portion 90 has openings 94, 96, 9S andv `100 stamped therein where opening 94 receives conductors 40 and 42 in opposed current carrying relation and in a similar manner, openings 96, 98 and 100 receive pairs of diode conductors M -46, 48-50, and 52-54 respectively. Each lamination of second portion 92 has openings 102, 104y and 106 therein which receive pairs of conductors 42--44, 46-48 and 50-52 respectively.

The tirst and second portions (shown exploded away from one another in Figure 5) therefore prow'de magnetic couplings identical to the individual coupling reactors ofFigure 2.V That is to say, the conductors are surrounded by magnetic material-in the same manner as if individualv reactors were used. Thus, conductor 42 is magnetically associated with its rst adjacent conductor 40 through lamination portion 90 While it is also magnetically associated with its second adjacent conductor'v44 through lamination portion 92. In a similar manner, each pair of adjacent diode conductors are linkedto one Vanother-"through a magnetic circuit. i

The manner in which an even number of diodes can be ,connected in la closed chain is shown inV Figures 6,17 and8.v The rst portion of the laminaiton stack is seen in the top View of Figure 6 as containing openings 108 through 1.14 while the second portion of the lamination stack 'of Figure 7 ncontains openings 116 through 122.` As described in Figure 5, the openings of the iirst lamination portion of Figure 6 receives a rst alternate pair of conductors while the openings of the second lamination portion of Figure 7` receives a second alternate pairof laminations. l

Therefore, when the first and second lamination portions are positioned with respect to one another as in Figure 8, it is clear that each alternate pair of conductors are connected and the'chain closes on itself as described in'Figure 3.

I n` the event that the coupling reactors are to be air gaps for reasons set forth inthe above'noted copending application, then, as shown in Figure 8a for the case of thelaminaitons of thetype used in Figure 5, a longitudinalicut `130 can be made through some or each of the laminations.

The manner in which thelaminations may be supported from the bus members is shown in Figures 9 and `l0 for the case of the closed chain system of Figures 6, 7 and 8.

Referring now to Figures 9 and 10, the rectifier assembly is supoprted from a frame member 132 of insulating material; IheframeI 132 supports a rst and second bus 134 and 136 which are bolted toframe 132 as by bolts 138 Vyand 140 for bus 136 of Figure 9 and are positioned on nut. plates 142, 144, 146 and 148. Buses ,134 and' 136 contain cooling conduits 135a-135Zv Vand 137a`137b respectively and support conductive diode receivngblocks such ras blocks 150 through 1,5 6 for bus 136 and four similar blocks such as block 158 for bus 134.

Each of' the diode receiving blocks are constructed as shown ,for block 15.8 of Figure 9 having tapped openings such as opening 1,60 for receiving their respective diode 4 169 (Figure 9) and bolted to the frame 132 by bolts 172 and 174.

The current balancing reactor laminations are supported from the buses 166 and 168 by the diode conductors as will be shown hereinafter and are comprised of a iirst portion 170 corresponding to the laminations of Figure 6, and a second portion 172 corresponding to the laminations of Figure 7. The laminations are preferably insulated from the buses in any desired manner.-

Since the pairs of adjacent conductors to vbe magnetically coupled must p ass throughthe laminations in opposite directions, all of the diodeconductors 'in which current is to pass from right to left, or diodes 24, 28,

32 and 36 (see'Figure 5)` are"conne`cted to bus 134 while l the other diodes 2,6, 30,34 and 38 Vare connected to bus 136. Therefore, each of diodes 24, 28, 32 andV 36, as specically shown for diode 36 in Figure 9, is connected through a respective current limiting fuse (fuse 176 for diodef36) and then "to diode conductor 52 which Vis 'insulated from bus 168 andthe laminations 170 and 172 yby insulating sleeve 178 'and insulating spacerr180 and the diode conductor then iselectrically connected to bus 166. Ina simliar manner, the remaining diodes 24, 28 and 32 of bus 134 are electrically connected to bus 166, passing through and being insulated from the bus 168and cores 1'70 and 172 by insulating structure such as insulating sleeves 182, 184 and l186 respectively.

In a similar manner, diode 26 being typical of diodes 26, H30, 34 and 38 s'electrically connected through fuse 188 to busbar'168 after passing through the cores 170 and 172."V Note that 'conductor' 42 of diode26 iselec'- t'rically insulated from bus 166 and laminations 1704 and 172 by insulating sleeve 190 and insulating spacer 192.y N From the foregoing, it is apparent that thel lamination structure is supported from bus bars 166 and 16,8 by conductors 40, 42, 44, 46, 48, 50, 52 and 54 which passl through the lamination structure and are fastened V,to

A the buses. Accordingly, the structurefis made'extremely.

member, and being bolted to their nut plates'by bolts Y similar to bolts 162 and 164.

The output bus is comprised of Erst and second eloncompact, accessible for maintenance and economical.

In the foregoing, I have described my invention only. in connectionfwith preferred embodiments thereof. Many variationsl and modifications of the principles of my vention "Within the scope'of the ydescription herein are obvious. Accordingly, I prefer to b ey bound not by the specificl disclosure herein butuonly bythe appending' claims.

' I claim:

l. A current Ibalancing reactor means for a plurality of parallelconnected diodes; Vsaid current balancing v'reactor meansodmprising a stack of magnetic laminations; each of said diodes having conductors extending theref from; each of said conductors being positioned adjacent another of said conductors; eachof said V conductors and a first of said conductors adjacent thereto extending through respective apertures in a rst portion` of said stack of magnetic laminations; each of said conductors and a second of said conductors adjacentthereto extending through respective apertures in a second portion kof said stack ,of magnetic laminations; each of said conductors adjacent to one Vanothercarrying current in an opposite direction; each of said conductors terminating on' a common bus conductor means; said current balancing stack of magnetic laminationsbeing supported from said bus conductor. means L 2. A" current balancing reactor means for a plurality of parallel connected diodes; saidcurrent balancing reactor mean-s comprising a stack of vmagnetic laminations;

each of said diodes having conductors Vextending there--` from; each of said conductors being positioned adjacent another of said conductors; each of said conductorsvand` fr is n s ing through respective apertures in a second portion of said stack of magnetic laminations; each of said conductors adjacent to one another carrying current in an oppoiirst bus portion; the'other of saiddiode conductors passing current through said stack in a direction opposite said first direction terminating at said second bus portion.V

3. A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of said'diodes having conductors extending therefrom; each of said conductors being positioned adjacent anotherof said conductors; said stack of magnetic laminations being comprised of a first and second portion; each of said firstand second portions of said stack of magnetic laminations including va first and second row of apertures extending parallel to one another; each of said conductors anda rst conductor adjacent thereto extending through a respective 'aperture of said 'rst portion of said stack of laminations; each of said conductors and a second conductor adjacent thereto extending through a respective aperture of said second portion of said stack of magnetic laminations; each of said adjacent conductors carrying current in an opposite direction.

4. A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising aV stack of magnetic laminations;

each of said diodes having conductors extending there` from; each of said conductors being positioned adjacent another of said conductors; said stack of magnetic 1aminations being comprised ofa first'and secondportio'n; each of said first and second` portions of said Astack of Vmagnetic laminations including a first and second row of apertures extending parallel to one another; Keach of said conductors and a first conductor adjacent thereto extending'through a respective aperture of said first yportion of said stack of laminations; eachV of said conductors and a second conductor 'adjacentvthereto extending through a respective aperture of lsaid second portionof said stack of magnetic laminations; cachot said adjacent conductors carryingcurrent in an opposite direction; each of said conductors being magnetically coupled through said stack ofmagnetic laminations. t

5. A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of said diodes having conductors extending therefrom; each of said conductors being positioned adjacent another of said conductors; said stack of magnetic 1aminations being comprised of a first and second portion; each of said first and second portions of said stack of magnetic laminations including a first and second row of apertures extending parallel' to one another; each of said conductors and a first conductor adjacent thereto extending through a respective aperture of said first portion of said stack of laminations;each of said conductors and a second conductor adjacent thereto extending through a respective apertureof said second portion of said stack of Vmagnetic laminations; each'of said adjacent conductors carrying current in an opposite direction; said stack of magnetic laminations operating as individual coupling reactors coupling said adjacent conductors to force equalcurrent distribution between their respective diodes.

6. A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations;

each of said diodes'having conductors extending therefrom; each of said conductors being positioned adjacent another of saidl conductors; said stack of magnetic 1amina'tions being comprised of afirst and second portion; each of said first and second? portions of said stack of magnetic laminations including a first and second row of apertures extending parallel to o ne another; each of said conductors and a first conductorv adjacent thereto extending through a respective aperture ofsaid first portion of said stack of laminations; each of said conductors and a second conductor adjacent thereto extending through a respective' aperture of said second portion of saidstack of magneticlaminations; each of said adjacent conductors carrying current in an opposite direction; each of said apertures in said first and second portions of said stack being aligned to allow' each of said conductors to' pass straight through said stack of laminations.

7.: A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of saiddiodes having conductors extending therefrom; each of said conductors being positioned adjacent another of said conductors; said stackof magnetic laminations being comprised of a first and second portion; each of said lirst and second portions'of said stack of magnetic laminations including a first and second row of apertures extending parallel to one another; each of said conductors and a first conductor Vadjacent thereto extending through a respective aperture of said first portion of said stack of laminations; each of said conductors and a second conductor adjacent thereto extending through a respective aperture of '.said second portion of said stack of magnetic laminations; each of said adjacent conductors Y carrying current in an opposite direction; said stack of magnetic laminations operating as individual coupling reactors coupling said adjacent conductors to force equal current distribution between their respective diodes; each 'of said apertures in said first and second portions of said stack being aligned to allow each of said conductors to pass straight through said stack of laminations.

- 8. A current balancing reactor means for a plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of saiddiodes having conductors extending therefrom; each of said 'conductorsvbeing positioned adjacent another of saidconductors; said stack of magnetic laminations being comprised of a first and second portion; each of said first and'secondportions of 'saidl stack of magnetic laminations? including a rst and second row of apertures extending parallel to one another; each of said conductors and a first conductor adjacent thereto extending through a respective aperture of said first portion of said stack of laminations; each of said conductors and a second conductor adjacent thereto extending through a respective aperture of said second portion of said stack of magnetic laminations; each of said adjacent conductors carrying current in an opposite direction; each of said conductors terminating on a common bus conductor means; said stack of laminations being supported from said bus conductor means.

9. A current balancing reactor means for aplurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of said diodes having conductors extending there-l from; each of said conductors being positioned adjacent rssrsctive aperture f Sad Second portion Qf Said Stack o f` magnetic laminations; each'of said adjacent conductors taurina current fallan opposite-ldirection; each of Said oondutors` terminating on la common bus conductor means; said st acktolflaminations being supported from fsaid bus conductor means; said bus conductor means beingcornprised of a first and second portion positioned adjacenta first and second face of said stack of magnetic laminations; alternately positioned of said conductors extending -,from said 4diodes passing current through said stack in a iirst direction terminating at said rst bus portion; the other of said alternately positioned conduc- 1041's passing current through said stack in a direction oppOtSitesaid first direction terminatingat said second bus portion.

' 10.1A current balancing reactormeans fora plurality of parallel connected diodes; said current balancing reactor means comprising a stack of magnetic laminations; each of said diodes `having conductors extending therefrom; each of said conductors being positioned adjacent another of said conductors; said stack `of magnetic laminations being comprised of a rst and second portion; each of said lirst and second` portions'of said stack of magnetic laminations including a first and second row of apertures extending parallel to one` another; each of said conductors and` a first'conductor adjacent thereto extending through a respective aperture of said first portion of said stack of laminati'ons; each of said conductors and a second conductor adjacent theretoextending through a respective aperture `of said second portion of said stack of magnetic laminations; each of said adjacent conductors carrying current in an opposite direction; said conductors being arranged to forma closed loop to thereby form a closed chain coupling system; each of said conductors terminating on a common bus conductor means; said Astack of laminations being supported from said bus conductor means.

11. Acurrent balancing reactor means for a plurality ofparallel connected diodes; said current balancing reactor means comprising a stack of-rnagneticrlamlnations; each of said diodes having ,conductors extending'therefrom; each'of said conductors beingpositioned adjacent another of said conductors;fsaid stack of magnetic laminations being comprised of a first andsecond portion; each Vof said lirstvand second portions of said stack of magnetic laminations including a first :and `second row of apertures extending parallel `to` one another; each of said conductors and a first` conductor adjacent thereto extending through a respective aperture of said first portion of said stack ofV laminations; cach of said conductors-and a second conductor adjacent thereto extending through a respective aperture of said second portion of said stack of magnetic laminations; each of said adjacent conductors carrying current in an opposite direction; each of said apertures in said first and second portions of said stack being aligned to alloweach of said conductors to pass i straight through saidI 'stachr of laminations; said 4conductQI-,Sbitls arranged t0 form a Closed loop foitherby form a Vclosecll chainfooupling system; each of'said conductors terminating on a common bus conductor means; said stach of laminations being supported from V-said bus @advertir means 1 2. A current balancing reactor means for a plurality of parallelg connected circuits; said current balancing reactor means comprising a stack of magnetic laminations; eachofgsaid circuits having conductors extending therefrom; each of said conductors beingpositioned adjacentanother of saidrconductors; each. of said conductors and a Afirst of said conductors adjacent thereto lextending through respective aperturesv ina first portion of said stack of magnetic laminations; each of said conductors `and a second; of said conductors :adjacent thereto extending throughjrespective apertures inA a second portion of said stack of magnetic laminations; each of said adjacent conductors carrying current in fan opposite direction; cach of said Vconductors terminating on la common bus conductor means; said current balancing stack of 4magnetic laminatio'ns beingysupported from said bus conductormeans.

13.` A- current balancing reactor means for a plurality` of parallel connected circuits; said current balancing reactor means comprising a stack of magnetic laminations;

eachrof said circuits having conductorsY extendingtherefrom; yeach ofsaid conductors being'positioned adiacent another of said conductors; said stack of magnetic laminations being comprised of a rst and second portion; each 'of said first and second portions of said stack of magnetic laminations including `a first and second `row of apertures extending parallel to one another; each of said conductors and a first conductor `adjacent thereto extending` through a respective aperture of said rst poltion of said stack of laminations; each of said conductors land a second conductor adjacent thereto extending through a respective apertureof said second portion of said stack of magnetic laminations; each of saidadjacent conductors. carrying current Vin an `opposite direction; each-of said conductors terminating on a commonbus conductor means; vsaid stack of l-aminations being supported from 4said bus conductor means; said bus conductor means being comprised of a first and second portion positioned adjacent ya first and second face of said stack of magnetic laminations; 'alternately positioned circuit conductors passing current through said stack :in a first direction terminatingat'fsaid first bus portion; the other of said circuit conductors passing current through said stack in a direc-j tion opposite said first direction terminating 4at said second bus portion, v

References Cited in the file of this patent UNITED STATES PATENTS 2,224,755 Werner v Dec. l0, 1940 

